var dengLu =document.querySelector('.dengLu');
var account =document.querySelector('.account');
var password =document.querySelector('.password');
var tip_one =document.querySelector('.tip_one');
var tip_two =document.querySelector('.tip_two');
var first = document.querySelector('.first');
var second =document.querySelector('.second');
account.onclick = function(){
    //   first.style.borderColor = red;
    alert('a');
};